Emulsion polymerization of vinylidene compounds in the presence of carbamates of polyamines



Patented Feb. 24, 1953 EMULSION" POLYMERIZATION 0F VINYL IDEN E COMLRGUNDS THE'Q PRESENCE OF" GARBAMATES. OF BOLA1WJN E S can A.- Uraneck and Alvin" Q." Rothl isberger; Berger, Tex assignors to? Phillips Petroleum Company; a' corporation dfi Delaware:

No'Dra'wingfi; Application Septemlier5; 1950", Serial No. 18313941 This invention relates to an improved process for polymerizing unsaturated organiccompounds While dispersed in anaqueousemulsion. Inione important aspect this invention relates to; the".

use of faster recipes at low 'polymerization te m peratures for efiecting. productionrofi synthetic: rubber by emulsion polymerization of'lconjugatedi diolefins.

With the increasing interest. in .low' tempera:- ture emulsion polymerization; many variations in recipes and procedurechavebeenndevelopedgim the interest of economy'and efiiciency addi-v tion to the attention given to producing pol-y meric materials. having the desiredi characteris tics. Recipes of theredoxztypey that; tions wherein both oxidizing; and reducingicom-r ponents are present, have beenwidely used; Oxii' dizing components frequently employed include: materials of a 'per0Xidic' nature, and. particul 1y compounds such as benzoyliperoxide and: on J mene hydroperoxide. Even 'though.anypertntidi c material might be expected to'iunctionain tha capacity of the oxidant in a redox emulsiorfi polymerization system, this is notnecessarilythe case since in some instances little; iflainy'; poly merization occurs While: in other" cases-With di-f ferent peroxides the reaction takes. place a a? satisfactory rate; Someperoxides mayfunot; fairly satisfactorilyat higher temperatures but? are of little value when it is: desired-to cany' ouif' polymerizations: at low temperatures, say'loel'owi the freezing point oi-water;

We have-now discovered that 'excellentpoly-- merization ratesare obtained-when "liquid -vinylidene com'pornds, polymerizable when dispersed in an aqueous medium; ar'e -dispersed in an aquaous medium andpolymerizedin thepr'esence oi a'=' polymerization catalyst composition comprising an organic peroxide-as an oxidant-ancl"ai'carba=-- mate of a polyamin'o compound as a=' reduc'tant1' In general, whensuch a carloama'te isemployed as a component of-"the -polymerization catalyst composition, polymerization occurs" at a more; uniform rate, particularly "in' the earlystagesiol" the reaction, than when the-correspondingpolye amino compound is used. With 'the latteri'com pounds, polymerization occursvery rapidly" at first and is- -o'ften followed -by'amarked deoreasei in the rate. In someihstancestiiere is-eventa cessation of thereaction before tlie dsiied cone glformulaz-lpolyamino" compound as activator.

1701mm; (o1. seen-84.7

z versl'on' is reaclied: This-rapid reaction; or'surg'e'; beginning-*makes temperature control difplant? operation. This problem is -a1le viated finrougl'ithe use of a" carbamate of a- Good ulti'-- mate conversions are realized when these activators aretused and,,inmany5 instances, thereonversion reached is equal to or. exceeds that ohtainecr when; polyethylene-polyamines are employ'edz It has also been found" that various batchesor flots of what" is purported: to be the same polyamino compound, such asvariouslot's of tetraethyl'e'nep'entamine; do not'e'xh'ibit' the v 7 same activity" when used" in what are otherwise identical polymerization recipes. When'such lots of poiya-mine: are. convertedito' the: carba'r-nate andthiscompound is then used as disclosed hereih",,1"nore reproducible results. are obtained, withou'tisuch unpredictable and'rncontroll'able variations; addition" tov theforegoing advantages, tnese recipes afford'a means for'effectingpolymutation: reactions in the absence of. heavy metafsal'ti activators; object of "this-invention is to. polymerize unsaturatedorganic' com ounds.

Anotherobject" of this inventionli's to. produce synthetic rubber.

further object" of this invention is to polymerize a monomeric material comprising aconjugatedidieneiwhil'edispersed in an aqueous medium.

Still another. objectof thisinvention is to effect rapid polymerization atIIoW polymerization temperatures of" monomeric. materials dispersed in.

bon. dioxidewitli apolyaminocompounds. Thesecompounds which serve asreductants for the polymerizationcan be employed as single compounds; or. mixtures l of homologous. compounds,

such as; carbamates of. hydrazine, ethylenedi-- amine,- diethyl'enetriamine,- 2',.-methy1-3.-azapen taile=lj5 diaminepN ('z hydroxyethyl)" 1,2"- ethanediarnine; N phenylethylen'ediamine, N cycloheXyl-N' (2 -a'minoethy1') 1;2 ethanediamine;

of the group consisting of and 1 and is 1 when r m is greater than 0. Each of the foregoing radicals (other than hydrogen) can be completely hydrocarbon in character, and R can be of mixed character when containing six or more carbon atoms, such as alkylcycloalkyl, aralkyl, alkaryl groups, and the like, and both R and X can also have non-hydrocarbon substituents, some of I which will have the effect of making the carbamates more water-soluble andless oil (hydrocarbon)-soluble; particularly useful non-hydrocarbon substituents include oxygen in the form of hydroxy and ether compounds, sulfur in similar compounds, (i. e., mercapto compounds and thioethers), and halogen compounds. The carbamates are prepared from the above described polyamino compounds, are preferably the mono.- carbamates, and probably can be represented by the formulae RHN(CHXCHXNH) MCHXCHX) nN(H) COOM I where M may be hydrogen or an alkali metal or ammonium. Carbon dioxide can also react with i one or more of the secondary. nitrogen atoms, thus forming dicarbamates, and similar higher polycarbamates. When R is hydrogen, the formula for the monocarbamate is frequently repree sented thus:

These compounds appear to act as reductants and/or activators in the polymerization mixture and no other activating ingredients, such as compounds of polyvalent-multivalent metals, nee be added in orderto obtain satisfactory and rapid polymerization of the monomeric material, EX:- cept as such compounds may fortuitously be present in the polymerization mixture. Similarly, no other reducing ingredient, such as a reducing sugar, need be added.

The carbamates are readily prepared in high yields by adding excesssolid or gaseous carbon dioxide to a polyamino compound, such as de-' scribed above, in the presence of a solvent such as water and/or an alcohol, preferably ethyl, a propyl, or a butyl alcohol. The amount of solvent employed will generally be in the range from 1 to parts per part of amine by weight. Carbon dioxide is added to the amine solution with constant stirring until heat is no longer evolved. Cooling is effected by any suitable means. During addition of the carbon dioxide the mixture takes on the appearance of a heavy,

viscous oil from which a white solid separates when additional carbon dioxide is introduced.

The solvent is removed by decantation, filtration, or other suitable means and the solid product is then washed with additional solvent and dried. When preparation of the carbamate is carried out in an open vessel, i. e., at atmospheric pressure, the product is predominantly the monccarbamate with only small amounts of the dicarbamate being formed. When the reaction is carried out under pressure, the reaction proceeds in the direction of the dicarbamate. This method for the preparation of carbamates is adapted from the method used by Mulvaney and Evans, Ind. Eng. Chem. 40, 393397 (1948).

The organic peroxide used as the oxidant component of the polymerization catalyst should have solubility properties such that the major portion of it is present in the liquid monomer phase, rather than in the aqueous medium, under the polymerization conditions. In general, two groups of organic peroxides can be used, those having the formula ROOl-I, known as hydroperoxides or hydroperoxymethanes, and those having the formula ROOR, where R in each instance is an organic radical. These two groups are not equivalents, however, and the hydroperoxides are preferred. The preferred hydroperoxides can be represented by the formula RRRf'COOI-I wherein R is selected from the group consisting of hydrogen and organic radicals, and each of R and R" is an organic radical, or RR" together comprise a tetramethylene or. pentamethylene group forming with the a cyclopentylor cyclohexylhydroperoxide. Each of R, R and R." can be completely hydrocarbon in character, and can be of mixed character, such as aralkyl, alkaryl, and the like, and can also have non-hydrocarbon substituents, some of which will have the effect of making them more water-soluble and less oil(hydrocarbon)-soluble; particularly useful non-hydrocarbon substituents include oxygen in the form of hydroxy and ether compounds, sulfur in similar compounds (1. e. mercapto compounds and thioethers), and halogen compounds. Examples of such hydroperoxides include diisopropyl hydroperoxide (isopropyl(dimethyl) -hydroperoxymethane) cumene hydroperoxide (phenyl (dimethyl) hydroperoxymethane), l-methyl-1-hydroperoxycyclopentane, tetralin hydroperoxide, phenylcyclohexane hydroperoxide, octahydrophenanthrene hydroperoxide,- diisopropylbenzene hydroperoxide (dimethyl (isopropylphenyl) hydroperoxymethane), methylethyl(ethoxyphenyl) hydroperoxymethane, methyldecyl (methylphenyl) hydroperoxymethane, dimethyldecyl hydroperoxymethane, methylchlorophenylphenylhydroperoxymethane, and tertiary-butylisopropylbenzene hydroperoxide (dimethyl (tertiary-butylphenyl) hydroperoxymethane). Such hydroperoxides can be easily prepared by simple oxidation, with free oxygen, of the corresponding hydrocarbon or hydrocarbon derivative, i. e. of the parent trisubstituted methane. The compound to be oxidized is placed in a reactor, heated to the desired temperature, and oxygen introduced at a controlled rate throughout the reaction period. The mixture is agitated during the reaction which is generally allowed to continue from about one to ten hours. The temperature employed is preferably maintained between 50 and C., although in some instances it might be desirable to operate outside this range, that is, at either higher or lower temperatures. At the conclusion of the reaction the oxidized mixture may be employed as such, that is, as a solution of the hydroperoxide composition in the parent compound, or unreacted compound may be stripped and the residual material employed. The major active ingredient in such a composition is the monohydroperoxide, or a mixture of monohydroperoxides. This hydroperoxide group appears to result from introduction arcane of two oxygen atoms between the carbon atom of the trisuhstituted methane and the single hydrogen atom attached thereto. Where there is another similar grouping inthe molecule, the usual method of production just outlined appears to produce only the monohydr'operoxide even though a dihydroperoxide appears to be structurally possible.- Thus, in a simple case, from such an oxidation of cli isopropyl benzene the. primary product appears to be dimethyl tiso'propylphenyl) hydrcperoxymethanei.

One large group of these hydroperoxymethanes is that group in which each. of the. three substituent groups is a hydrocarbon radical. One. of the subgroups of these compounds is: the alkaryldialkyl hydroperoxymethanes, in which. the two alkyl groups are relatively short, 1. e. have from one to three or four carbon atoms each, including dimethyl(tertiarybutylphenyl)"hydroperoxwmethane, dimethyl diisopropyl phenyl)hydroper oxymethane, dimethyl (isopropylphenyl) hydroperoxymethane, dimethyl (dodecylphenyl) hydroperoxymethane, dimethyl-(methylphenyl)hydroeroxymethane, and corresponding methylethyl and diethyl compounds, and the like; Another subgroup includes at least one long alkyl' group" directly attached. to the hydroperoxymethane, such as methyldecyl.(methylphenyl) hydroperoxymethane, ethyldecylphenylhydroperoxymethane, and the like. trialkyl compounds, such as: dimethyldecylhydroperoxyrnethane, the like; aralky-l compounds, such as 1-phenyl-3-methyl3-hydroperoxybutane, can also be considered to be members ofthis group. A further subgroup includes alkyldi'aryl compounds, such as methyldiphenylhydroperoxy methane, methylphenyltolylhydroperoxymethane, and the like. A. further subgroup is the triaryl compounds, such as triphenylhydroperoxymethane, tritolylhydroperoxymethane, and the like. A 7

further subgroup comprises cyclopentyl and cyclohexyl hydroperoxides, such. as result from oxidation of cyclohexanc', methylcyclopentane, and phenylcyclohexane, and. compounds containing condensed ring structures such as 1,2,3,4,4a,9,10-,- lGa-octahydrophenanthrene, which forms the corresponding hydroperoxide upon oxidation, or'- ganic peroxides and hydroperoxides, preferably will have a total of not more than thirty carbon atoms per molecule, and the most active hydroperoxides usually have at least ten to twelve carbon atoms per molecule. Mixtures of these peroxides and/r hydrop'eroxide's can be used, as desired.

The amount of carbamate used to obtain opti mum results is dependent upon other ingredients in the recipe. Preferred results are usually obtained with between 0.02 and parts by weight of the carbamate per 100 parts of monomeric material. 1

The amount of organic peroxide used to obtain an optimum reaction rate will depend upon the polymerization recipe employed and upon the reaction conditions. The amount is generally expressed in millimols per 100 parts of monomeric material, using in each instance the same units of weight throughout, i. a, when the monomeric material is measured in pounds the hydro peroxide is measured in millipound mols. The same is true for other ingredients inthe polymerization recipe. An optimum rate of polymerization is usually obtained with the amount of hydroperoxymethane between 0.1 and 10 milli moTs per 10s parts by weight of monomer-do material.

Still another subgroup includes The monomeric material polymerized to produce polymers by the process of this invention comprises unsaturated organic compounds which generally contain the characteristic structure and, inv most cases, have at least one of the disconnected. valencies attached to an electronegativeg oup}. that is, a group which increases the polar character of the molecule such as: a chlorine group or an organic group containing a double' or triple bond such as vinyl, phenyl, cyano, carboxy or the like. Included in this class of monomers are the conjugated butadienes or 1,3- butadienes such as butadiene (1,3-butadiene), 2,3-dimethyl 1,3butadiene, isoprene, piperylene, 3 -.furyl-l,3-.butadiene, 3-methoxy-l,3-butadiene and the like; haloprenes, such as chloroprene (2- chloro-1 ,3butadiene),. bromoprene, methylchloroprene (-2-chloro-3-methyl-L3-butadiene), and the like; aryl olefins such as. styrene, various alkyl styrenes, p.-chlorostyrene, p-methoxystyrene, alpha-methylstyrene, vinylnaphthalene and similar derivatives thereof, and the like; acrylic and substituted acrylic acid and their esters, nitriles and amides such as acrylic acid, methacrylic acid, methyl acrylate, ethyl acrylate, methyl alpha-chloro-acrylate, methyl. methacrylate, ethyl methacrylate, butyl methacrylate,

methyl ethacrylate, acrylonitrile, methacrylonitrile, methacrylamide and the like, methyl isopropenyl ketone, methyl vinyl ketone, methyl vinyl ether, vinylethinyl alkyl carbinols, vinyl acetate, vinyl chloride, vinylidene chloride, vinylfurane, vinylcarbazole, vinylacetylene and other unsaturated hydrocarbons, esters, alcohols, acids, ethers, etc., of the types described. Such unsaturated compound may be polymerized alone, in

- which case simple linear polymers are formed, or

mixtures of two or more of such compounds which are copolymerizable with each other in aqueous emulsion may be polymerized to form linear copolymers.

The present invention is directed primarily to. the production of polymers. of conjugated dienes, which have physical properties classifying them as synthetic rubber, and the invention is particularly applicable to the polymerization of hydrocarbon monomeric materials. Such materials include 1,3-butadiene and other conjugated. diolefin hydrocarbons having not more than six carbon atoms per molecule, halogen derivatives, such as chloroprene, fluoroprene, and the like, either alone, in admixture with each other, or together with minor amounts of unsaturated compounds which are copolymerizable therewith in aqueous emulsion, such as styrene, alpha methylstyrene, vinyltoluene chlorostyrene, etc, In this case the products of the polymerization are high molecular weight linear polymers and copolymers which are rubbery in character and may be called synthetic rubber. Although, as can be readily deduced from the foregoing, there is a host of possible reactants, the most readily and commercially available monomers at present are butadiene itself (1,3-butadiene) and styrene. The invention will, therefore, be more particularly discussed and exemplified with reference to these typical reactants. With these specific monomers, it is usually preferred to use them together, in relative ratios of butadiene to styrene between 65:35 and :10 by weight.

It is generally preferred that the emulsion be ofan oil in water type, with the ratio of aqueous medium to monomeric material between about 0.521 and about 2.75:1, in parts by weight. It is frequently desirable to include water-soluble components in the aqueous phase, particularly when the polymerization temperatures are below freezing. Inorganic salts and alcohols can be so used. Alcohols which are applicable, when operating at low temperatures, comprise water-soluble compounds of both the monohydric and polyhydric types, and include methyl alcohol, ethylene glycol, glycerine, erythritol, and the like. The amount of alcoholic ingredient used in a polymerization recipe must be sufficient to prevent freezing of the aqueous phase and generally ranges from 20 to 80 parts per 100 parts of monomers charged. In most cases the amount of water employed is sufficient to make the total quantity of the alcohol-water mixture equal 150 to 200 parts. In cases where it is desired to use a larger quantity of the alcohol-water mixture, say around 250 parts, the amount of alcohol may be increased to as much as 120 parts. It is preferred that the alcohol be such that it is substantially insoluble in the non-aqueous phase, and that 90 per cent, or more, of the alcohol present be in the aqueous phase. A high-boiling alcohol such as glycerine is difficult to recover from the resulting serum; a low-boiling alcohol such as methanol is easily removed and frequently preferred. Other aliphatic alcohols of higher boiling point than methanol, such as a propanol, are frequently less satisfactory. If the resulting latex tends to gel at low reaction temperatures, a larger proportion of aqueous phase should be used. In the practice of the invention suitable means will be necessary to establish and maintain an emulsion and to remove reaction heat to maintain a desired reaction temperature. The polymerization can be conducted in batches, semicontinuously, or continuously. The total pressure on the reactants is preferably at least as great as the total vapor pressure of the mixture, so that the initial reactants will be present in liquid phase. Usually 50 to 98 per cent of the monomeric material is polymerized.

In preparing synthetic rubber by polymerizing conjugated dienes, by the process of this invention, it is usually desirable to use a polymerization modifying agent, as is usually true in other polymerizations to produce synthetic rubber. Preferred polymerization modifiers for use in the process of the present invention are alkyl mercaptans, and these may be of primary, secondary, or tertiary configurations, and generally range from C8 to C16 compounds, but may have more or fewer carbon atoms per molecule. Mixtures or blends or mercaptans are also frequently considered desirable and in many cases are preferred to the pure compounds. The amount'ofmercaptan employed will vary, depending upon the particular compound or blend chosen, the operating temperature, the freezing point depressant employed, and the results desired. In general, the greater modification is obtained when operating at low temperatures and therefore a smaller amount of mercaptan is added to yield a product, of a given Mooney value, than is used at higher temperatures. In the case of tertiary mercaptans, such as tertiary C12 mercaptans, blends of tertiary C12, C14, and C16 mercaptans, and the like, satisfactory modification is obtained with 0.05 to 0.3 part mercaptan per 100 parts monomers, but smaller or larger amounts may be employed in some instances. In fact, amounts as large as 2.0 parts per 100 parts of monomers may be used. Thus the amount of mercaptan is adjusted to suit the case at hand.

One of the advantages of the polymerization recipes, as disclosed herein, is that they are ap plicable for use in the production of high solids latices, i. e., latices resulting from the use of a smaller amount of aqueous medium than is generally used in conventional polymerization procedures. For this type of operation the ratio of aqueous phase to monomeric material will generally be in the range from 0.521 to 1:1 and the extent of conversion will generally range from '70 per cent to substantially complete conversion.

Emulsifying agents which are applicable in these low temperature polymerizations are materials such as potassium laurate, potassium oleate, and the like, and salts of rosin acids, either alone or in admixture with each other. However, other emulsifying agents, such as nonionic emulsifying agents, salts of alkyl aromatic sulfonic acids, salts of alkyl sulfates, and the like which will produce favorable results under conditions of the reaction, can also be used in practicing the invention, either alone or in admixture with soaps. The amount and kind of emulsifier used to obtain optimum results is somewhat dependent upon the relative amounts of monomeric material and aqueous phase, the reaction temperature, and the other ingredients of the polymerization mixture. Usually an amount between about 0.3 and 5 parts per parts of monomeric material will be found to be sufficient.

The pH of the aqueous phase may be varied over a rather wide range without producing deleterious effects on the conversion rate or the properties of the polymer. In general the pH may be within the range from 9 to 12 and it may be advantageous to have a pH higher than 12 in some instances. In most cases optimum results are obtained if the pH is 10 or higher.

When carrying out polymerization reactions according to the process of this invention, it is frequently considered desirable to include an electrolyte in the system, such as potassium chloride, trlsodium phosphate, or other salt which will not produce deleterious effects. One function of an electrolyte is to increase the fluidity of the latex. Generally the amount of such salt will not exceed one part per 100 parts of monomers.

We generally use the carbamates discussed herein as activators in polymerization recipes at low polymerization temperatures, i. e., from about 30 C. to well below the freezing point of water, such as -40 C. or lower. However, temperatures as high as 60 C. or even higher may be employed if desired.

Advantages of this invention are illustrated by the following examples. The reactants, and their proportions, and the other specific ingredi cuts of the recipes are presented as being typical and should not be construed to limit the invention unduly.

EXAMPLE I Monocarbamates of diethylenetriamine, triethylenetetramine, and tetraethylenepentamine were prepared and employed in a series of butadiene-styrene copolymerizations at 5 C. For comparative purposes runs were also made using the corresponding polyethylenepolyamines. These carbamates were prepared by the following procedure.

A 10 per cent solution of the amine in methanol was placed in an Erlenmeyer flask fitted with an inlet tube containing amercury pressure'seal. Carbon dioxide "was introduced'in the gaseous form from a cylinder. The exact amount of carbon dioxide added was determined by the total increase in weight of the reaction vessel. As soon as the required amount of carbon-dioxide had been added, thevesselewas opened and the contents werepoured into anequalvolume oflether. The carbamate thus precipitated was filtered from the solution, washed with several portions of ether, and dried under vacuum over phosphorus pentoxide'and paraffin. Yields obtained by this method ranged from 70"to-80 per cent.

10 conversion is obtained and there is a smaller decrease in the polymerization rate as polymerization proceeds.

' EXAMPLE II The recipeof Example I was followed except that 0.76 part of either the carbamate or amine activator Was used instead of 0.5 part and the pH of the emulsifier was 11. Monoand dicar bamates of diethylenetriamine and triethylenetetramine were employed as activators as 'well as the corresponding amines. Polymerizations were effected at 5 C. The following results were obtained:

Conversion, Percent Rate per Hour -at- 1 Hr. 3 Hrs. 6Hrs. Hm 1 Hr. 3 Hrs. oHi-s.

Diethylenetriamine Inonocarb amate 7 23 40 85 '7 7. T 6.7 3. 5 Diethylenetriamine di'carbamatc 4 19 31 76 4 6:3: 5:2. 3. 2 Diethylenetrlamine 17 35 56 97 17 11. 7 9. 4 4. 0 .Triethylenetetramine monocarbamate.- 37 55 93 15 12.3 9. 2 3. 9 Triethylenetetramine dicarbamate 10 26 44 92 10 8. 7 7. 3 3. 8 Triethylenetetramine 22 47 70 99 22 15. 7 .16. 7 4. 1

The polymerization recipe was as follows:

Parts by weight Butadiene '70 Styrene 30 Water 180 Soap flakes 1 .5

(pH of soap solution) 11.0-11.4

Potassium chloride 0.4

Mercaptan blenol 0.1

Tert.-butylisopropylbenzene hydroperoxide 0.42 (2.025 millimols) Amine or carbamate 0.5 I v 1 Potassium Ofiice Rubber Reserve Soap. D

A blend of tertiary C12. C14, and C aliphatic mercaptans in a ratio of 3 1 1 parts by weight.

Produced by oxidation of tert. butyl-lsoprop lbenzene, and considered to be t-C H C H C(CH O H.

A mixture of the emulsifying agent, water, and potassium chloride was prepared and potassium hydroxide added to adjust the pI-I to 11.0-11.4. A solution of the hydroperoxide and mercaptan in styrene was then introduced, followed by the The reactor was pressured to 30-- butadiene. pounds per square inch gauge with nitrogen and the temperature adjusted to 5 C. Ten parts of Water was added to the carbamate or amine to make a solution which was charged to the reactor. Polymerization was effected in the conventional manner while the temperature was held at 5 C. The following results were obtained:

These data show that when carbamates are employed, the polymerization rate at the beginning of the reaction is more gradual than when the corresponding amines are used and yet all runs give good ultimate conversions.

EXAMPLE III The followingrecipe was employed forcarrying out the copolymerization .ofbutadiene with styrene at 5 C.:

Partsby weight Butadiene Styrene ..30 Water, total 180 Rosin soap, K salt 1 4.7 Trisodium phosphate,

NazPO; 0.5 Potassium hydroxide 0.153

.(pHsoap solution) 11.9 Mercaptan blend 0.25

Tert.-butylisopropylbenzene hydroperoxide 3 0.0624 (0.3 millimol) Tetraethylenepentamine monocarbamate 0.035 (0.15 millimol) D1csinate S449; soapprepared from a partially hydrogenated rosin As in' Example I.

3 As in Example I.

The procedure given in Example I was fol- In all cases, the ultimate conversion was as high or higher with the carbamate than with the corresponding amine. The carbamates also show,

greater uniformity in conversion rate, i. e. although the initial polymerization rate is lower When using the carbamate than when using the lowed. Two additional runs were made using 0.225 and 0.3 millimols, respectively, of the carbamate but otherwise the recipe was the same as that given above. For comparative purposes a control run was made using the same recipe but corresponding polyamine, the same high ultimate substituting 0.15 millimol tetraethylenepentamine '1 1 12 for the carbamate. The following results were Tetraethylenepentamineobtained: CO: reaction product Variable messes: Activator ggigi g Rate :1 5 a As in Examgle I:

In addition to runs made using the activator Mm 3 m 22 3 22 solutions prepared by the methods described Type mols Hrs. Hrs. Hrs. Hrs. Hrs. Hrs. above, three runs were also made using samples of the carbamate which had been previously pre- Carhamate 0.15 9 36 72 3 3.6 3.3 10 pared and isolated. These samples are desiggg:: 8? g3 nated as original carbamate in the following Amine (control) 0.15 28 53 68 0. a 5. s 3. 1 table which shows the results obtained with various millimol charges of the activator prepared by 1 'Ietraethylenepentamine monocarbamate. different methods, 2 Tetraethylenepentamine.

The above data show the regularity of con- Activate, C nversi n, R p fl r version rate with the carbamate activator in contrast to the rapid polymerization rate in the a beginning of the reaction when the correspondi g a f ing amine is used as the activator. The data 7 also show a better ultimate conversion when the 0,225 27 50 85 9 H 5 carbamate is present, Na:OO|+HCl 0.15 22 41 80 7.3 6.8 5.3 32;; 1; a :2 a it EXAMPLE IV Dry Ice 0:15 15 31 84 5 52 3.5 0.075 7 17 01 2s 28 2.5 Butadiene and styrene were copolymerized at 04225 0 59 90 10 9 8 5 C. according to the following recipe: Ongmawarbamate{ 8:6? 13 35 g 2 2:; Parts by weight 555531333:3:333:33:Z3 EXAMPLE Water, total 130 30 A series of runs was made to polymerize vari- Rosin Soap, K salt 1 g ous monomeric mater als. These runs were consodium chloride 0.4 ducted at a polymerization temperature of 0 Potassium hydroxide 0151 C., us1ng, in each instance, the following baslc (pH soap solution) 11.7 l'eclpei Mercaptan blend 2 0.25 y I Tert.-butylisopropylbenzene Component Parts by v eight hydroperoxide 3 0.0624 (0.3 millimol) Tetraethylenep tami e v$???ff?fi'if?fjjjj '1 8 monocarbamate or 0.035 (0.15 millimol) Potassium ORR p 5 Tetraethylenepentamine- 0.028 (0.15 millimol) gi 33 40 Mixed artistes-es new ne ates"; 0 2 %H' t-butylisopropylbenzene hydroperoxident. 0 208 (1 millirnol) a As in Example I: Tepa carbamate 1 0.46 (1.6 millimols) The procedure of Example I was used and the :p t p following results were obtained: o caRreJaofiioliiimpiigiiuct of 1 m0] tetraethylenepent'nmme and 2.2 mols Conversion, Percent Rate per Hour at- 3 5.5 10 22 3 5.5 10 Hrs. Hrs. Hrs. Hrs. Hrs. Hrs. Hrs.

The run with the carbamate not Only shows a The following polymerization (per cent conmore uniform conversion rate but it reached a version) results were obtained. higher conversion.

Polymerization data for various monomers poly- EXAMPLE V 1 merized in recipes activated with tetraethylene- Attempts were made to prepare act vator solupentamine carbamate tions similar to the preceding amine carbamate solutions by either generating carbon dioxide in the presence of an aqueous amine solution or by Run A B o D E F G adding gaseous carbon dioxide to an aqueous amine solution. The following polymerization Parts recipe was used: Parts by weight I 70 70 Butadiene 7 fiii g q aeryme. 100 an 0n N 30. $5223. gg Blclrtgdieilg-i- Z8 70 Rosin soap,Ksalt 4.7 Trisodium phosphate Conversion, Percent Na3PO4 0.4: Potassium hydroxide 0.128 25 0 28 53 32 (pH soap solution) 11.8 6 g7 5 Mercaptan blend 0.25 2s 0 97 100 99 I: i I .Tert.-butylisopropylbenzene 33 92 hydroperoxide 0.0707 (0.34 millimol) lhe following run was carried out with hydrazine carbamate as the 'reduct'ant. "The following recipe was employed, at a polymerization temperature of '0.

Parts by weight Butadiene 70 Styrene 30 Water I 180 Fatty acid soap, K'sal't 1 5 Mercaptan blend 0.25 T e r t. butylisopropylbenzene hydroperoxide "0.42 '(Zmillimolsl Hydrazine carbamate; 0.304(4mi1limols) 1 Pet ssium Ofllce Rubber Reserve Soap. 2 A blend of tertiary C12, 014 and Cu aliphatic mercaptans in a ratio of 3:1:1 parts by weight.

The following results were obtained:

Time Hours I, Conversion, f Percent l s, 6 94.5.Wlunlwu... s- 152 EXAMPLE VIII The following run was conducted with the monocarbamate of aminoethylethano'lam-i-ne (Z-hydroxyethyl)-1,2-ethaned-iamine as the reductant. The recipe employed "was as follows, and the polymerization temperature was 5 C.

.Parts by weight Butadiene 70 Styrene Water 180 Potassium soap, ORR .5 Na3PO4-12H2O 0.4

Tert.-butylisopropylbenzene hydroperoxide 0.208 =(1:m illim ol.) Allzyl mercaptan :blend 0.25 Carbamate h 0.29 6 (-Zmill-imQls) A conversion of '25 per cent, of the monomeric material, was obtained in 7.5 hours, and per cent in 16.5 hours.

As will 'be evident to those skilled in the 'ar t, various modifications of this invention can he made, or foliowed, in the light of the foregoing disclosure anddiscussion, without departing from the spirit or scope of the disclosure or from the scope of the claims.

We claim:

1. In the production of synthetic rubber by the polymerization of a momomeric material comprising a major portion of 1,3-butadiene and a minor portion of styrene while dispersed in an aqueous emulsion in the presence act a catalyst composition at a polymerization temperature, the improvement which comprises conducting said polymerization with the pH of said aqueous emulsion between 9 and 12 and using .as said catalyst composition 0.1 to 10 m'illimol' of 1 14 t-'C'4I-I9CsH4C'(CH3)202I-I together With 0&2 to 5 parts of a-carbamate of 'tetraethylenepentamine, said amounts being per parts by weight of said monomeric material.

2. In the polymerization of a monomeric material comprising an organic compound having an active group and polymerizable while dispersed in an aqueous medium in the presence of an oxidant and a reducing composition at a polymerization temperature, the improvement which comprises using as said oxidant 0.1to 10 millimo'ls of an organic peroxide which i effective as an oxidant in said polymerization and present in said monomer'ic material in a greater concentration than in said aqueous medium and selected from the group consisting of compounds having the formula ROGR'and compounds having the formula ROOH wherein R is an organic radical, and as said reducing composition 0.02 to'5 parts of a carbamate of a polyamino compound having the formula RZI-INKCHXCHXNH) m'('CHXCHX) NI-I2 where 'R contains not more than eight carbon atoms and is of the group consisting of hydrogen, aliphatic, oycloaliphatic, aromatic, olefinic, and cycloolefinic radicals, and each X contains ot more than three carbon atoms and is of the group consisting of hydrogen and aliphatic radicals, 'm is an integer between 0 and 8, inclusive, and n is an integer of the group consisting of 0 and 1 and is 1 when m is greater than 0, said amounts being per parts by weight of said monomeric material.

3. The process of claim 2 in which said organic peroxide :is a trisubstituted hydroperoxymethane.

4. The process of claim 2 in which said organic peroxide "is t-CHeCsH4C(CI-Is) 202R 5. The process, of claim 2 in which said carbamate is a monocarbamate of tetraethylenepentamine.

6. The process of claim 2 in which said carbamate is a carbamate of diethylenetriamine.

7. The process of claim 2 in which said carbamate is a carbamate of triethylenetriamine.

8. The process of claim 2 in which said carbamate is a carbamate of hydrazine.

9. The process of claim 2 in which said carbamate is a carbamate of N-(Z-hydroxyethyD- 1,2-ethanediamine.

10. A process for polymerizing a monomeric material comprising a conjugated diene having from four to six carbon atoms per molecule, which comprises polymerizing said monomeric material while dispersed in an aqueous medium in the presence of a polymerization catalyst composition comprising an oxidant and a 'redu'ctan't in which said oxidant is a organic 'hydroperoxide havingten to thirty carbon atoms per molecule effective as an oxidant in said polymerization and present 'in said monomeric material in a greater'concentration than in said aqueous me dium and having the formula ROOI-I wherein R is an organic radical, and said reductant is a carbamate of a polyamino compound having the formula RI-IN(CHXCIIXNH) mKCHXCHX) NI-I2 where R contains not more than eight carbon atoms and is of the group consisting of hydrogen, aliphatic, cyclcaliphatic, aromatic, olefinic, and cycloolel'lnic radicals, and each X contains not more than three carbon atoms and is of the group consisting of hydrogen and aliphatic radicals, m is an integer between 0 and 8, inclusive,

and n is an integer of the group consisting of 0 and 1 and is 1 when m is greater than 0.

11. A process for polymerizing a monomeric material comprising an unsaturated organic compound having an active group and polymerizable when dispersed in an aqueous medium, which comprises polymerizing said monomeric material while dispersed in an aqueous medium in the presence of a polymerization catalyst composition comprising an oxidant and a reductant in which said oxidant is an organic hydroperoxide having ten to thirty carbon atoms per molecule efiective as an oxidant in said polymerization and present in said monomeric material in a greater concentration than in said aqueous medium and havin the formula ROOH wherein R is an organic radical, and said reductant is a carbamate of a polyamino compound having the formula RHN (CHXCHXNH) 711(CHXCHX) NH:

where R contains not more than eight carbon atoms and is of the group consisting of hydrogen, aliphatic, cycloaliphati-c, aromatic, olefinic, and cycloolefinic radicals, and each X contains not more than three carbon atoms and is of the group consisting of hydrogen and aliphatic radicals, m is an integer between 0 and 8, inclusive, and n is an integer of the group consisting of 0 and 1 and is 1 when m is greater than 0.

12. A process for polymerizing a monomeric material comprising a conjugated diene having from four to six carbon atoms per molecule, which comprises polymerizing said monomeric material while dispersed in an aqueous medium in the presence of a polymerization catalyst composition comprising an oxidant and a reductant in which said oxidant is an organic hydroperoxide having ten to thirty carbon atoms per molecule effective as an oxidant in said polymerization and present in said monomeric material in a greater concentration than in said aqueous medium and having the formula ROOH wherein R is an organic radical, and said reductant is a carbamate of tetraethylenepentamine.

13. A process for the polymerization of a monomeric material comprising an organic compound having an active group and polymerizable while dispersed in an aqueous medium, which comprises polymerizing said monomeric material while dispersed in the presence of an emulsifying agent in an aqueous medium at a polymerization temperature in the presence of an oxidant-reductant polymerization catalyst composition comprising a trisubstituted hydroperoxymethane as said oxidant and a carbamate of an ethylene polyamine having not more than nine ethylene groups as said reductant.

14. The process of claim 13 in which said monomeric material comprises a major portion of a conjugated diolefin hydrocarbon having four to six carbon atoms per molecule and said hydroperoxymethane is an alkaryl-dialkyl hydroperoxymethane.

15. In the polymerization of a monomeric material comprising an organic compound having an active group and polymerizable while dispersed in an aqueous medium at a polymerization temperature in the presence of an oxidant-reductant polymerization catalyst comprising an organic peroxide and a reductant, said organic peroxide being effective as an oxidant in said polymerization and present in said monomeric material in a greater concentration than in said aqueous me dium and selected from the group consisting of compounds having the formula ROOR and compounds having the formula ROOH wherein R is an organic radical, the improvement which comprises using as said reductant a carbamate of a polyamino compound having the formula RHN(CHXCHXNH)m(CHXCHX)nNH2 Where R contains not more than eight carbon atoms and is of the group consisting of hydrogen, aliphatic, cycloaliphatic, aromatic, olefinic, and cycloolefinic radicals, and each X contains not more than three carbon atoms and is of the group consisting of hydrogen and aliphatic radicals, m is an integer between 0 and 8, inclusive, and n is an integer of the group consisting of 0 and 1 and is 1 when m is greater than 0.

16. A process for the polymerization of a monomeric material comprising an organic compound having an active group and polymerizable while dispersed in an aqueous medium, which comprises polymerizing said monomeric material while dispersed in the presence of an emulsifying agent in an aqueous medium having a pH between 9 and 12 at a polymerization temperature between 30 and -40 C. in the presence of a polymerization catalyst composition comprising 0.1 to 10 millimols of an organic peroxide which is effective as an oxidant in said polymerization and present in said monomeric material in a greater concentration than in said aqueous medium and selected from the group consisting of compounds having the formula ROOR and compounds having the formula ROOH wherein R is an organic radical, and 0.02 to 5 parts by weight of a carbamate of an ethylenepolyamine having not more than nine ethylene groups, said amounts being per parts by weight of said monomeric material.

17. A process for the production of synthetic rubber, which comprises polymerizing a monomeric material comprising a major portion of a conjugated diene having four to six, inclusive, carbon atoms per molecule while dispersed in the presence of an emulsifying agent in an aqueous medium at a polymerization temperature between 30 and 40 C. in the presence of a polymerization catalyst composition comprising 0.1 to 10 millimols of a trisubstituted hydroperoxymethane and 0.02 to 5 parts by weight of a carbamate of an ethylenepolyamine having not more than nine ethylene groups, said amounts being per 100 parts by weight of said monomeric material.

CARL A. URANECK. ALVIN C. ROTHLISBERGER.

REFERENCES CITED The following references are of record in the file of this patent:

OTHER REFERENCES Whitby et al., Rubber Age, vol. 65, No. 5, Aug. 1949, page 545. 

1. IN THE PRODUCTION OF SYNTHETIC RUBBER BY THE POLYMERIZATION OF A MONOMERIC MATERIAL COMPRISING A MAJOR PORTION OF 1,3-BUTADIENE AND A MINOR PORTION OF STYRENE WHILE DISPERSED IN AN AQUEOUS EMULSION IN THE PRESENCE OF A CATALYST COMPOSITION AT A POLYMERIZATION TEMPERATURE, THE IMPROVEMENT WHICH COMPRISES CONDUCTING SAID POLYMERIZATION WITH THE PH OF SAID AQUEOUS EMULSION BETWEEN 9 AND 12 AND USING AS SAID CATALYST COMPOSITION 0.1 TO 10 MILLIMOLS OF T-C4H9C6H4C(CH3)2O2H TOGETHER WITH 0.02 TO 5 PARTS OF A CARBAMATE OF TETRAETHYLENEPENTAMINE, SAID AMOUNTS BEING PER 100 PARTS BY WEIGHT OF SAID MONOMERIC MATERIAL. 